1. Field of the Invention
This invention relates to an apparatus and method of making resilient air compressible apparatus, more particularly, this invention is an apparatus and method of making air compressible apparatus that are used to lift objects and can withstand pressure and shock.
2. State of the Art
Rubber bumpers, cushions, air compressible apparatus and the like have been used for many applications. Some of these applications require air to be drawn in and out, in air compressible apparatus fashion, but others require a constant air amount to provide resistance as the volume of the item is changed. These products tend to be used in failure sensitive applications, for example, as shock absorbers in vehicular applications or as the lift provider for jacks and the like. Consequently, one of the constant problems with these products is the expense required to create a high quality product. Therefore, there exists a need to build a high quality failure resistant device that is inexpensive, does not require a lot of material, is fairly easy to reproduce, yet results in a high quality product.
In most of the applications now developed for the conventional cushions, rubber deformable section is held onto a frame by a bead, an embedded wire molded into the rubber portion that fits into a receiving part of the frame. Although this standard way of molding rubber has worked satisfactorily for years, beads are known to separate from the frame, causing a potential for failure of the device. Examples of the conventional construction are found in Engineering Manual and Design Guide Firestone Products Company, Natalville, Ind. (date of publication unknown) and the Vehicular Applications Engineering Manual Goodyear Air Spring Applications, Greenburg, Ohio (date of publication unknown). The bead referred to above will be exemplified on page 6 of the Firestone publication and page 13 of the Goodyear publication. Although neither publication is represented as being exhaustive in its coverage of possible configurations for the rubber and metal interface, the only one shown is one variation or another of the bead type joint.
A variation on the cushion theme is the use of the air compressible apparatus as a lifting device in a jack or the like. One such application is shown in U.S. Pat. No. 6,082,708, the disclosure of which is incorporated herein. A bead joint is shown as the preferred embodiment. Therefore the ends of the rubber member are not affixed to the lifting plate. Although the bead joint usually works well in such applications, it may fail unexpectedly.
The air compressible apparatus, as defined in this invention, is a resilient object that is able to withstand both high pressure and shock. This invention provides for a method to make resilient air compressible apparatus with little material, is inexpensive, not laborious, and easy to manufacture. The final products are resilient air compressible apparatus made of high quality materials that have a long useful life.
Once made, the resilient air compressible apparatus may be filled with air and used as a lifting mechanism to lift objects, such as a car. Although air is commonly used to fill air compressible apparatus, this invention, as broadly used herein, also provides for the use of liquids to fill the air compressible apparatus. The use of air compressible apparatus in pneumatic springs are not uncommon. In fact, the earliest available records of using air compressible apparatus in pneumatic springs is in 1847. However, as technology increased, so did the formation and application of the air compressible apparatus.
Resilient air compressible apparatus may also be used as pneumatic springs or shock absorbers. The resilient air compressible apparatus utilize the pressure of the gas as the force medium of the spring. The compressibility of the gas provides the desired elasticity for suspension use in machines such as delicate equipment, hydraulic power units, vibrating instruments, vehicles to reduce the amount of road shock and vibration and other similar applications. The resilient air compressible apparatus may also be used to separate large objects. For example, the air compressible apparatus may be used to separate two metal components, hence acting as a separator and a pneumatic spring.
As stated above, the use of air compressible apparatus in pneumatic springs are not uncommon. However, the air compressible apparatus used today require additional materials to build and are therefore costly and require more labor hours to build. For example, some air compressible apparatus used today require girdle rings or girdle hoops, which this invention does not require. Bead plates are also additional materials required by the air compressible apparatus used today, but not required by this invention.
This invention provides an apparatus and method for lifting items or buffering items against shock using an air compensable apparatus that includes two rigid ends having the resilient material sandwiched therein, and a resilient body. In a first aspect of this invention, the resilient air compressible apparatus has a resilient member formed from a cylinder of resilient material with a first end and a second end. The cylinder defines an interior and an exterior. The apparatus includes a plurality of rigid disks each having a top surface and a bottom surface. In the preferred embodiment, the top surfaces are planar or smooth and the bottom surfaces are shaped and configured to be able to grip a portion of the resilient material between opposing bottom surfaces on pairs of rigid disks. The first rigid disk is disposed in the interior at the first end of the resilient member with the bottom surface facing upwardly. The second rigid disk is disposed on the exterior of the first end of the resilient member with the bottom surface facing downwardly positioned substantially over the first rigid disk and substantially aligned therewith. A portion of the first end of the resilient member is interposed between the bottom surface of the first rigid disk and the bottom surface of the second rigid disk. A third rigid disk is disposed in the interior of the second end of the resilient member with the bottom surface facing downwardly. A fourth rigid disk is disposed on the outside of the second end of the resilient member with the bottom surface facing upwardly and positioned substantially over the third rigid disk and substantially aligned therewith. A portion of the second end of the resilient member is interposed between the bottom surface of the third rigid disk and the bottom surface of the fourth rigid disk.
A passageway for the entrance and exit of air can be disposed in the fourth rigid disk and continue through the third rigid disk to communicate with the interior of the resilient air compressible apparatus. Alternatively, the apparatus can include a bottom plate connected to the fourth rigid disk. The bottom plate can have the passageway and include the inlet used to connect to a supply of compressed air. The inlet can be suitable for connecting to a rubber hose that connects to the supply of compressed air. The resilient member can comprise at least a first layer of resilient material bonded to a second layer of resilient material. In the preferred embodiment, the resilient member is formed from a multiple layers of rubber and reinforced rubber material.
In another aspect of this invention, the resilient air compressible apparatus described above is utilized in a lifting apparatus having the resilient air compressible apparatus disposed between a bottom lifting surface member and a top lifting surface member. The resilient air compressible apparatus has a first side and a second side. The first side of the resilient air compressible apparatus is connected to the top lifting surface member and the second side of the resilient air compressible apparatus is connected to the bottom lifting surface member. An inlet for admitting pressurized air into the resilient air compressible apparatus is connected thereto. For safety and control purposes, a control valve is disposed between the inlet and a source of pressurized air. For additional lift, a single resilient air compressible apparatus can be combined with a second resilient air compressible apparatus that is in constant air communication with the first compressible apparatus. A bottom side wall can be peripherally disposed about the bottom lifting surface member and a top side wall can be peripherally disposed about the top lifting surface member. If desired or determined to be necessary depending on the application of the lifting apparatus, the top and bottom side walls can have a plurality of support members thereon.